Nicole Kidman didn't think Meryl Streep would join 'Big Little Lies'.

The 68-year-old multi-Academy Award winning actress was announced to be joining the hit HBO show as the mother-in-law of Nicole's character, Celeste Wright, last month, but despite the part being written with the screen legend in mind, her new co-stars never expected her to sign up for the TV series.

Speaking to 'Entertainment Tonight', Nicole, 50, said: ''Reese [Witherspoon] and I were just [thinking], 'She would be so amazing in the role!'

''We didn't think we'd get her. It was written for her and we wanted her. It really is her standing up and going, 'I support you as women and I believe in you'.

''I think that's a big statement from her. We're determined to give her an extraordinary experience. She's had a lot of experiences so we just want to make it fun for her and vibrant and exciting.''

It's not only Nicole who cannot believe they have secured 'The Post' actress, as her co-star Laura Dern can't stop talking about her casting.

She said: ''It's amazing! When I tell anyone in my life that Meryl Streep is joining us, it's incredible!''

During the first season of the David E. Kelley drama based on the Liane Moriarty novel, it was revealed that Nicole's abusive husband Perry Wright [Alexander Skarsgard] had died, and Meryl's character is said to be ''concerned for the well-being of her grandchildren'' following his passing.

HBO previously said of the show's second season: ''[It will explore the] malignancy of lies, the durability of friendships, the fragility of marriage and, of course, the vicious ferocity of sound parenting. Relationships will fray, loyalties will erode ... the potential for emotional and bodily injury shall loom.''

Despite Perry's death in season one, Alexander is set to make an appearance in the second season in some capacity, though it is unknown how his character will feature.

The first season of 'Big Little Lies' received critical acclaim when it aired early last year, specifically for the realistic portrayal of domestic violence between Alexander's character and his on-screen wife Celeste.